Not this one. The room jerked hard as if startled. And then it was over, maybe a few seconds. No damage here, but it definitely got our attention.
[I changed the title from 4.8 to 4.6. The original USGS maps - below - said 4.8.]
UPDATE 7:23am From the US Geological Survey Earthquake Page
 |
| Map from USGS |
 |
| Map from USGS |
To put this into context, here's a list of earthquakes today in Anchorage from the Alaska Earthquake Information Center at the University of Alaska Fairbanks. The give the 7:02 quake a 4.6.
 |
| Screen shot at 8:20am 5/16/2012 |
This historic summary is from the same page as the second map.
Tectonic Summary Seismotectonics of the Aleutian Arc The Aleutian arc extends about 3,000 km from the Gulf of Alaska to the Kamchatka Peninsula. It marks the region where the Pacific plate subducts into the mantle beneath the North America plate. This subduction is responsible for the generation of the Aleutian Islands and the deep offshore Aleutian Trench. Relative to a fixed North America plate, the Pacific plate is moving northwest at a rate that increases from about 55 mm per year at the arc's eastern edge to 75 mm per year near its western terminus. In the east, the convergence of the plates is nearly perpendicular to the plate boundary. However, because of the boundary's curvature, as one travels westward along the arc, the subduction becomes more and more oblique to the boundary until the relative plate motion becomes parallel to the arc at the Near Islands near its western edge. Subduction zones such as the Aleutian arc are geologically complex and produce numerous earthquakes from multiple sources. Deformation of the overriding North America plate generates shallow crustal earthquakes, whereas slip at the interface of the plates generates interplate earthquakes that extend from near the base of the trench to depths of 40 to 60 km. At greater depths, Aleutian arc earthquakes occur within the subducting Pacific plate and can reach depths of 300 km. Since 1900, six great earthquakes (M8.3 or larger) have occurred along the Aleutian Trench, Alaska Peninsula, and Gulf of Alaska: M8.4 1906 Rat Islands; M 8.6 1938 Shumagin Islands; M8.6 1946 Unimak Island; M8.6 1957 Andreanof Islands; M 9.2 1964 Prince William Sound; and M8.7 1965 Rat Islands.
There is a great map on the adn.com site. The epicenter is off Klatt, between Toby's house and mine. I heard a rumbling sound first, sort of like heavy equipment in the street, and was walking toward the window to check on it when I felt the sharp jolt.
ReplyDeleteI watched Hacking Democracy last night. Wow! This was a real eye-opener. Everyone who trusts the security of our elections should see this. Thanks for putting up the link (in your May 13 Suppose Someone Found a Body post).
Here's the link to Hacking Democracy.
ReplyDelete